1. Field of the Invention
The present invention relates generally to a seat reclining device for automotive vehicle seats and more specifically to a motor-driven seat reclining device provided with a Taumel mechanism (planetary gear type angle adjusting mechanism).
2. Description of the Prior Art
In a seat reclining device of motor driven type called a power seat, a large gear reduction ratio can be obtained by use of a Taumel mechanism or a planetary gear type angle adjusting mechanism. This mechanism is disclosed in U.S. Pat. No. 3,401,979 by way of example, which is incorporated herein by reference. The prior-art seat reclining device usually comprises at least one base frame fixed on one side of a seat cushion; a reclining arm pivotally supported by the base frame via a Taumel mechanism with its reclining arm end fixed to one side of a seat back; a motor unit mounted on the base frame to drive the reclining arm via the Taumel mechanism; and a reclining gear fixed to one axle end of the Taumel mechanism and driven by the motor unit via a pinion attached to a reduction gear of the motor unit.
In the prior-art seat reclining device, the reclining arm, the reclining gear, the Taumel mechanism, etc. are arranged on the outside surface of the base frame together with the motor unit as disclosed in Japanese Published Unexamined (Kokai) Utility Model Appli. Nos. 56-103253, 60-48846 and 60-163058 or on the inside surface of the reclining arm together with the motor unit as disclosed in Japanese Published Unexamined (Kokai) Utility Model Appli. Nos. 58-185947 and 59-115948. Therefore, there exist problems in that the width of the seat provided with the reclining device is large and further it is rather difficult to fully trim the vehicle seat for improvement in external appearance. In addition, where various power devices (driven by motors) are required for small-sized passenger cars there exists another problem in that it is difficult to mount a magazine rack, a door arm rest, a window power device, etc. within the passenger compartment, because a space between a vehicle door and a seat side is too narrow.